This invention relates to interstitial heating of tissue and in particular to heating of a solid mass within a body of a living being by means of an expandable chamber positioned interstitially within the solid mass. As used herein the term "interstitial" means situated between the cellular elements of a structure.
Various methods of interstitial necrosis are known that involve puncturing of a solid organ and insertion of a non-expandable interstitial device into the solid organ. The interstitial device may be used for electro-surgery, cryo-ablation, laser ablation, or alcohol injection.
Balloon catheters are known in which an expandable, heatable balloon mounted on a catheter shaft can be used as a heat source within a blood vessel during or after angioplasty. These balloon catheters are described in detail in Lennox et al., U.S. Pat. No. 4,955,377, the entire disclosure of which is hereby incorporated herein by reference. Such balloon catheters can also be used in nonvascular applications such as hyperthermia treatment of benign or malignant tumors, or enlargement of the prostate gland. Heat from the balloon destroys undesired cells, which are eventually absorbed into the patient's body.